Method and apparatus for treating tobacco

ABSTRACT

Tobacco is introduced into the top of a vertical chamber and allowed to fall therethrough by gravity. Steam is simultaneously introduced into the chamber and into contact with the tobacco in order to condition it. The steam treated tobacco falls by gravity from the chamber onto a vibratory conveyor and excess moisture vapor is removed by an exhaust system in association with the conveyor. If shredded tobacco is used, the process effects delamination of the shreds and consequent increase in filling capacity. The process is applicable to treat tobacco leaf prior to de-stemming and de-veining thereby minimizing breakage and the production of fines. Mechanical agitating means may be provided within the chamber.

United States Patent Waller 1 July 3, 1973 [54] METHOD AND APPARATUS FOR 3.392.922 7/1968 Lindgren 239/683 x TREATING TOBACCO [75] Inventor: Charles R. Waller, Winston-Salem, pmfmry l i N C Assistant Examiner-John F. Pitrelh Attorney-Albert H. Pendleton, Fred T. W1l1|ams [73] Assignee: R. J. Reynolds Company, et a1.

Winston-Salem, NC. 22 Filed: Nov. 8, 1971 [57] ABSTRACT Tobacco is introduced into the top of a vertical cham- [211 App! l96601 her and allowed to fall therethrough by gravity. Steam is simultaneously introduced into the chamber and into [52] US. Cl. 131/138, 131/133 R, 131/140 R contact with the tobacco in order to condition it. The [51] Int. Cl A24b 03/12 steam treated tobacco falls by gravity from the cham- [58] Field of Search 131/ 138, 133 R, 133 A, ber onto a vibratory conveyor and excess moisture 131/140 R, 140 A, 149, 139; 239/559, 567, 683 vapor is removed by an exhaust system in association with the conveyor. 1f shredded tobacco is used, the pro- [56] References Cited cess effects delamination of the shreds and consequent UNITED STATES PATENTS increase in filling capacity. The process is applicable to 446 441 2/1891 Frost 131/139 treat tobacco leaf prior to de'stemming and de'veining 1,9201107 7 1935 Richardson.. 131/133 A thereby minimizing beakage and Pmductio of 2,596,183 5/1952 131/133 RUX fines. Mechanical agitating means may be provided 2,707,690 5/1955 Pearson... 131/140 R ux within the chamber. 2,954,038 9/1960 Girarduj .1 239/559 X Li K ago

11 Claims, 6 Drawing Figures METHOD AND APPARATUS FOR TREATING TOBACCO BACKGROUND AND OBJECTS OF THE INVENTION In the manufacture of tobacco products, it is sometimes necessary to subject the tobacco to treatment with steam at various stages in the overall process. For example, steaming of tobacco leaves prior to destemming and de-veining minimizes breakage and the production of fines. Also, in the preparation of tobacco for use in the manufacture of cigarettes, it is usual practice to de-stem and de-vein the tobacco leaves and then cut or shred the leaves to a suitable size. This cutting or shredding operation results in a product in which a percentage of the shreds or strands are laminated together by virtue of the pressures incident to cutting. These laminated shreds are relatively large and are not desirable in tobaccos used in the manufacture of cigarettes. In the past, freshly cut tobacco has been treated for the purpose of effecting shred delamination. However, such prior methods have involved passing the freshly shredded tobacco through substantially horizontally arranged rotating drums into which steam is introduced. These drums are very large and in commercial practice require a considerable amount of floor space and are expensive to operate and maintain. In

' these devices the steam does not effectively contact all of the tobacco particles while they are in the drum and a high degree of delamination is not achieved.

Accordingly, one object of this invention is the provision of a process and apparatus for the conditioning of tobacco by the use of steam.

A further object of this invention is the provision of a process and apparatus for loosening up tobacco in the form of cut filler and in the form of bundles of cured leaves thereby increasing the ease with which the tobacco may be handled in subsequent process steps.

A further object of this invention is the provision of a process and apparatus for treating shredded tobacco which is effective for delaminating the shreds.

A further object of this invention is the provision of a process and apparatus for steam conditioning tobacco which requires a minimum amount of factory space and may be operated with a minimum of supervision and maintenance.

A further object of this invention is the provision of a process and apparatus which is effective not only to delaminate the shreds but consequently to increase the filling capacity of the tobacco.

A further object of this invention is the provision of a process and apparatus for treating tobacco leaves with steam to minimize breakage and the production of fines in subsequent de-stemming and de-veining operations.

A further object of this invention is the provision o a process and apparatus suitable for the application of flavorants and other additives to tobacco.

A still further object of this invention is the provision of a process and apparatus which is particularly amenable to high flow rates of tobacco, the short residence time in the steaming zone having the effect of minimizing the loss of flavorants.

Further and additional objects of this invention will appear from the following description, accompanying drawings and the appended claims.

GENERAL DESCRIPTION OF THE INVENTION In accordance with one embodiment of this invention, there is provided a process of treating tobacco which comprises continuously introducing tobacco into an upper portion of a vertically arranged steaming zone. The tobacco in the form of leaves or shreds is allowed to fall by gravity through said zone in a loose, noncompacted state to a lower portion. Simultaneously, a stream of steam is introduced into the zone and passed directly into contact with the downwardly flowing stream of tobacco. The steamed tobacco is withdrawn from a lower portion of the zone. The rate of flow of tobacco into the treating zone and the rate of flow of steam are preferably so adjusted that the temperature of the tobacco withdrawn is in the range of between about 55 and 105 C., most preferably between about and C. Under these conditions of treatment and in the processing of shredded tobacco, the steam has the effect of separating the lamina in those shreds that are laminated and at the same time the flavor and aroma of the product obtained from the process are not adversely affected. This delamination procedure also has the net effect of increasing at least to some degree the filling capacity of the tobacco product. The steam moistened tobacco is discharged onto a suitable conveyor, preferably of the vibratory type, and passed through an exhaust zone whereby excess moisture in the form of water vapor is separated from the treated tobacco.

Another aspect of this invention resides in the apparatus that is employed for effecting the process generally indicated above. The apparatus comprises a vertically arranged chamber having sidewalls and upper and lower ends. Means such as a conveyor belt are provided for continuously introducing tobacco into the upper end of the chamber for loose noncompacted gravity flow in a vertical direction therethrough and means for continuously removing the treated tobacco from the lower end of the chamber. The steaming means preferably comprises one or more elongated conduits each having a multitude of orifices for introducing steam into the chamber for a substantial distance throughout its vertical length. In a preferred form, the steam orifices in the lower portions of the conduits are directed in an upward direction and those in the upper portions are directed in a downward direction. This arrangement tends to confine the introduced steam to the intermediate zone within the chamber and the net buoyancy effect of the steam is minimized whereby the free gravity flow of the tobacco through the apparatus at a high rate is permitted. One modification of the apparatus particularly suitable for processing tobacco shreds includes a plurality of agitator elements suspended in the steam-treating chamber in order to insure that the loose shredded tobacco introduced therein is broken up to permit full exposure of the tobacco shreds to the steam.

It will be appreciated that the process and apparatus of this invention are suitable for use in the treatment of any type of tobacco, whether it be in the form of leaves or shreds of the green leaf or the cured type, including burley, flue-cured or oriental tobacco. The process is also suitable for treating reconstituted tobacco in the form of broken sheets or shreds. Also, if desired, suitable flavorants may be incorporated into the tobacco while it is undergoing the steaming operation. While it is preferred to introduce the steam into the chamber a more efficient conditioning of the-tobacco leaf or sheets or delamination of shredded tobacco than has heretofore been obtained in prior art devices where the tobacco is rolled through a horizontally arranged steaming chamber or drum.

It is preferred that the tobacco moistened by the steam be discharged from the chamber by gravity directly onto a vibratory conveyor which has the effect of maintaining the tobacco in the loose, fluffed-up condition as it is being transported to the next processing step. When processing shredded tobacco, a hood and an exhaust fan are preferably provided over the vibratory conveyor to prevent excess moisture from escaping into the factory area, and to remove excess water vapor which surrounds the mass of tobacco as it emerges from the chamber.

DESCRIPTION OF THE DRAWINGS For a more complete understanding of this invention, reference will now be made to the accompanying drawings in which:

FIG. 1 is a vertical sectional schematic view of one form of apparatus that may be employed for carrying out the process of this invention;

FIG. 2 is a sectional view taken along the line 22 of FIG. 1;

FIGS. 3 and 4 are enlarged detailed fragmentary views of a lower and an upper section, respectively, of one of the steam conduits used in the apparatus shown in FIG. 1;

FIG. 5 is a sectional view of the upper end of a modified form of the apparatus shown in FIG. 1 illustrating a mechanical agitating means which is advantageous under certain conditions and represents a modification of this invention; and

FIG. 6 is a sectional view taken along the line 6-6 of FIG. 5.

With more particular reference to the drawings, the apparatus comprises a vertical chamber 10 having upwardly extending parallel sidewalls 12 spaced by rounded sidewalls 14, thereby providing a chamber which is roughly oval in horizontal cross-section. Chamber 10 has an upper end 16, which may or may not be open, and a lower open end 18. A belt conveyor 20 is arranged for introducing tobacco into the top central portion of the chamber adjacent the upper end 16, and a vibratory conveyor 22 is provided for moving the steamed tobacco from the process to further treatment as may be desired. The chamber 10 is provided with an access door 24 in one of its sidewalls 12. A hood 26 and exhaust fan 28 are provided in association with the vibratory conveyor- 22 to remove moist air from the steam treated tobacco discharged from the chamber.

The steam for the chamber is introduced through conduit 32 which terminates in a pair of standpipes 34 and 36 which extend vertically through substantially the entire height of the chamber 10. The standpipes 34 and 36 are closed at their bottom ends and each is provided with a multiplicity of steam ejection orifices 38 (see FIGS. 3 and 4) vertically and radially spaced for a substantial distance throughout the length of the pipes in the chamber. A large number of these orifices are provided in each of the pipes 34 and 36 so that the tobacco falling through the chamber will be intimately contacted with steam. While satisfactory results may be achieved if the orifices are arranged to direct the jets in a substantially horizontal direction, it is preferred that the orifices 38 in the lower half of pipes 34 and 36 be formed in such a manner (see FIG. 3) that they direct the steam in a generally upward direction such as 45 from the horizontal and that the orifices in the upper ends be formed to direct the steam in a generally downward direction, e.g., 45 from the horizontal. This arrangement tends to confine the steam in the intermediate zone of the chamber thereby enhancing its effectiveness.

The vibratory conveyor 22 may be of any type well known to the art, one example being that disclosed in Carrier et al. U.S. Pat. No. 2,958,228 issued Nov. 1, 1960. It includes a conveyor tray 40 vibrated by a motor and eccentric weight drive 42 and supported on a fixed base 44 by means of a plurality of leaf springs or flexible nylon strips 46.

In operation of the apparatus shown in FIGS. 1 to 3, tobacco in leaf or shredded form is introduced continuously into the open end 16 of the chamber 10 and steam is simultaneously passed through the conduit 32, the steam pipes 34 and 36, and the orifices 38 in such a manner that the steam uniformly contacts the tobacco that falls in a loose, noncompacted condition downwardly through the chamber 10. In the case of shreds, the steam treatment causes the tobacco to become fluffy and a substantial portion of the laminated shreds are delaminated by the treatment. The delaminated shreds fall through the open end 18 onto the tray 22 and are passed to subsequent operations under the hood 26 whereby wet steam and moist air are removed by the exhaust fan 30 while the tobacco remains in the fluffed condition.

SPECIFIC EXAMPLE In one specific embodiment a chamber 10 is provided 9 feet high with a cross-sectional dimension of l X 2.5 feet and rounded ends as shown in FIG. 2. It is equipped with two 9-foot standpipes, each having 225 l/l6 inch I.D. orifices distributed over the lower 6% foot portion of each. The orifices in the lower half of each pipe were directed upwardly (see FIG. 3) and those in the upper half were directed downwardly (see FIG. 4), each at angles of about 45 from the horizontal. Freshly shredded cured tobacco (i.e., cut filler) containing laminated particles and some stem material was introduced into the top of the chamber 10 at ambient temperature (i.e., about 30 C.) at the rate of 12,500 lbs. per hour. High pressure steam 140 p.s.i.g.) was introduced to the conduit 32 and the pipes 34 and 36 at the rate of about 1,800 lbs. per hour. Under these conditions, the temperature of the tobacco discharged from the bottom end 18 of the chamber 10 was at a temperature of about C. The treatment resulted in a reduction of the laminated shreds in the tobacco by about 40 percent with a corresponding filling capacity increase of about 3 percent. The stem material in the treated cut filler was puffed to a significant degree to permit it to be separated by a subsequent winnowing MODIFICATIONS With reference to FIGS. 5 and 6, these show essen- 5 tially the same apparatus as shown in FIGS. 1 to 4 except that a mechanical means has been provided for insuring that any loose clumps of tobacco introduced into the top of the chamber on conveyor 20 are broken up during the fall through said chamber thereby permitting thorough contact of the tobacco with the steam escaping from the orifices 38 in the standpipes 34 and 36. In the embodiment shown, this device comprises a rotating camshaft 48 driven by a motor 50 mounted adjacent the upper end 16 of the chamber 10. A plurality of eccentric plates 52 are secured in spaced relationship to the shaft 48 and for rotation therewith. A stationary rod 54 is mounted above and parallel with the shaft 48. A plurality of levers 56 are pivotally mounted on the rod 54 and are urged against the surfaces of the eccentric plates 52 by gravity. Suspended from the ends of the levers 56 are a plurality of stainless steel chains 58 which depend into the chamber 10. The bottom ends of the chains hang free. Thus, when the camformed incident to a shredding operation.

3. The process of claim 1 in which said tobacco is leaf tobacco.

4. The process of claim 1 in which said tobacco while falling and being contacted with said steam in said zone is also subjected to mechanical agitation.

5. A process of treating tobacco which comprises continuously introducing a stream of shredded tobacco containing laminated shreds of leaf tobacco formed in- 10 cident to a shredding operation into an upper end portion of a vertically arranged elongated steaming zone having vertical side walls, allowing the shredded tobacco so introduced to gravity fall in a loose, noncompacted state through said zone from said upper portion to a lower open end portion thereof and between said walls, introducing steam into said zone through a multiplicity of orifices vertically spaced from each other whereby said steam intimately contacts and moistens the shredded tobacco falling through said zone and whereby the tobacco is heated to a temperature between about 55 and 105 C. and delamination is effected, continuously removing the resulting tobacco in a fluffed and delaminated condition from the lower portion of said zone, and thereafter subjecting the shaft 48 is rotated by the motor, suitably at a rate of fluffed tobacco to partial drying.

about 40 to 100 rpm, the eccentrics 52 exert a camming action on the levers and cause the levers 56 and the chains 58 to move up and down and sideways in separate vertical parallel planes, each of which is parallel to the direction of movement of the tobacco on the conveyor 20. This back-and-forth and up-and-down movement by the several chains breaks up any clumps that may be introduced into or form in the top of the chamber 10 so that the described contact of steam with the tobacco shreds will be more efficient. It will, of

course, be apparent that other agitating methods can be employed, one such being a plurality of chain-like elements suspended from a rotating crankshaft mounted for rotation adjacent the upper end of the chamber.

While several embodiments of this invention have been described in the foregoing, it will be apparent that many modifications may be made without departing from the spirit and scope of the accompanying claims.

What is claimed is:

1. A process of treating tobacco which comprises continuously introducing a stream of tobacco into an upper portion of a vertically arranged steam treating zone, allowing the tobacco so introduced to fall by gravity in a loose non-compacted condition through a gaseous atmosphere within said zone from said upper portion to a lower portion thereof, introducing steam into said zone at a plurality of vertically spaced locations for intimate contact with the tobacco falling through said zone whereby said tobacco is uniformly moistened and heated to a temperature between about 55 and 105 C., continuously removing the resulting tobacco in a loose fluffed-up condition from the lower portion of said zone, and thereafter subjecting the fluffed tobacco to partial drying.

2. The process of claim 1 in which said tobacco is shredded tobacco containing laminated tobacco shreds 6. The process of claim 5 in which a portion of the steam is introduced into the upper portion of said zone and is directed downwardly and another portion of the steam is introduced into the lower portion of said zone 30 and is directed upwardly.

7. The process of claim 5 in which the steamed and removed tobacco is subjected to mechanical vibration during the partial drying step.

8. The process of claim 5 wherein the tobacco during contact with said steam in said zone is subjected to mechanical agitation.

9. The process of claim 8 in which said agitation is provided by agitator elements reciprocating in a vertical direction in said zone.

40 10. A tobacco treating apparatus comprising a vertisaid chamber, discharge means including a vibratory conveyor adjacent said lower open end for receiving the tobacco falling through said chamber in a loose fluffed-up condition and for removing the fluffed-up shredded tobacco from said chamber, means within said chamber having a multiplicity of vertically spaced orifices for introducing steam into said chamber for contact with the shredded tobacco flowing therethrough, and an exhaust hood associated with said vibratory conveyor for exhausting excess moisture from the removed tobacco while in the loose fluffed-up condition.

11. The apparatus recited in claim 10 including tobacco agitation elements in the upper end of said chamber mounted for vertical reciprocation within said 0 chamber in contact with the loose tobacco flowing therethrough. 

1. A process of treating tobacco which comprises continuously introducing a stream of tobacco into an upper portion of a vertically arranged steam treating zone, allowing the tobacco so introduced to fall by gravity in a loose non-compacted condition through a gaseous atmosphere within said zone from said upper portion to a lower portion thereof, introducing steam into said zone at a plurality of vertically spaced locations for intimate contact with the tobacco falling through said zone whereby said tobacco is uniformly moistened and heated to a temperature between about 55* and 105* C., continuously removing the resulting tobacco in a loose fluffed-up condition from the lower portion of said zone, and thereafter subjecting the fluffed tobacco to partial drying.
 2. The process of claim 1 in which said tobacco is shredded tobacco containing laminated tobacco shreds formed incident to a shredding operation.
 3. The process of claim 1 in which said tobacco is leaf tobacco.
 4. The process of claim 1 in which said tobacco while falling and being contacted with said steam in said zone is also subjected to mechanical agitation.
 5. A process of treating tobacco which comprises continuously introducing a stream of shredded tobacco containing laminated shreds of leaf tobacco formed incident to a shredding operation into an upper end portion of a vertically arranged elongated steaming zone having vertical side walls, allowing the shredded tobacco so introduced to gravity fall in a loose, noncompacted state through said zone from said upper portion to a lower open end portion thereof and between said walls, introducing steam into said zone through a multiplicity of orifices vertically spaced from each other whereby said steam intimately contacts and moistens the shredded tobacco falling through said zone and whereby the tobacco is heated to a temperature between about 55 and 105* C. and delamination is effected, continuously removing the resulting tobacco in a fluffed and delaminated condition from the lower portion of said zone, and thereafter subjecting the fluffed tobacco to partial drying.
 6. The process of claim 5 in which a portion of the steam is introduced into the upper portion of said zone and is directed downwardly and another portion of the steam is introduced into the lower portion of said zone and is directed upwardly.
 7. The process of claim 5 in which the steamed and removed tobacco is subjected to mechanical vibration during the partial drying step.
 8. The process of claim 5 wherein the tobacco during contact with said steam in said zone is subjected to mechanical agitation.
 9. The process of claim 8 in which said agitation is provided by agitator elements reciprocating in a vertical direction in said zone.
 10. A tobacco treating apparatus comprising a vertically arranged chamber having side walls and upper And lower ends, means for continuously introducing shredded tobacco into said upper end for loose, noncompacted gravity flow in a vertical direction through said chamber, discharge means including a vibratory conveyor adjacent said lower open end for receiving the tobacco falling through said chamber in a loose fluffed-up condition and for removing the fluffed-up shredded tobacco from said chamber, means within said chamber having a multiplicity of vertically spaced orifices for introducing steam into said chamber for contact with the shredded tobacco flowing therethrough, and an exhaust hood associated with said vibratory conveyor for exhausting excess moisture from the removed tobacco while in the loose fluffed-up condition.
 11. The apparatus recited in claim 10 including tobacco agitation elements in the upper end of said chamber mounted for vertical reciprocation within said chamber in contact with the loose tobacco flowing therethrough. 